Method of making wood mold dies



Apfl 25, 1933. c. B. NoRRls Er Al. .I 1,905,048

METHOD OF MAKING'WOOD MOLD DIES April 25, 1933 c. B. NoRRls Er AL METHOD OF MAKING WOOD MOLD DIES s sheets-sheet 2 Fi1ed Apri1 23 1930 Vig?.

April 25, 1933- c. afNoRRls` ET Al.

METHOD 0F` MAKING WOOD MOLD DIES Fi1e1 Apri1 2s. 195o l:s sheets-sheet 5 Patented Apr. 2`5, 1933 UNITED STATES Parana*- OFFICE ('}HA..B1'.ESB. NORBIS, FRANK M. CUBRAN', AND HENDRIK W. VAN STEENWYK, OF GRAND RAPIDS, MIGHIGAN, ASSIGNORS TO HASKELITE MANUFACTURING CORPORATION, A

CORPORATION OF NEW YORK METHOD OF MAKING WOOD MOLD DIES Application legl April 23, 1930. Serial No. 446,656.

The present invention relates to dies for molding plywood panels and has for its object to improve such dies and their method or manufacture.

The various features of novelty whereby our invention is characterized will hereinafter be pointed out with particularity in` the claims; but, for a full understanding of our invention and of 'its objects and advantages, reference may be had to the following detailed description taken in connection with the accompanying drawings, wherein:

Figure 1 is a plan view of the electrodeposited shell or plate conforming to the original carving, the dotted lines in the corners marking the gores that are afterwards cut away; Fig. 2is a vertical section through the shell or late after it has been formed into a pan; ig. 3 is a view similar to Fig. 2 showmg a shell to form the working face of a die member, or a master pattern for such a shell; Fig. 4 is a section through a mold apparatus having a shell like that in Fig. 3 therein; Fig. 5 is a diagrammatic view illustrating the devices of Fig. 4 in a heating .oven and a pouring means for delivering molten metal thereto; Fig. 6 is a crosssection through a completed die, after pouring and finishing, together with a second mold apparatus and a complementary die member cast upon the first die member; Fig. 7 is a section, on a larger scale, through a ragment of the first die, illustrating an expedient to avoidclose fitting of the two dies at any desired points; Fig. 8 is a top plan view of the shell provided with an attachment to help form a somewhat different form of mold; Fig. 9 is a vertical section, on a larger scale than Fig. 8, showing the shell in an assembly ready for pouring; and Fig. 10 is a view slmilar to Fig. 9, showing a still further modification.

In the art to which the present invention relates a carving in wood is usually made; a wax impression is taken of the carving; and a plate or shell is electro-deposited upon the wax impression. In accordance with .considerably larger t our invention this plate or shell is made an the design; the part bearing the design A and corresponding in size to the face of the die to be made, indicated at 1 in Fig. 1, being completely/'surrounded by a border portion 2. Gores defined by the dotted lines 3, 3 in Fig. 1 arethen cut out of the corners of the border portion and the remaining sect-ions of the border portion are bent up and soldered together at their meeting edges; thereby producing a an having the design in the upper face of t e bottom wall and having sides composed of the marginal sections 2. In other words, the inside of the pan is smooth, whereas the outside is the rough face of the electro late.

The inside of the pan is then covered with a very thin layer of wax over which graphite is dusted, and a copper shell 4 is electrodepositedl on the inner face of the pan, so treated. This copper shell has the design A1 on the under slde of the bottom, the u per face of the bottom of the shellbeing t e rough one. This shell may be used as a master when backed with electrotype metal, or as part of an actual die. When the shell is used as a master, wax impressions are made and dusted with graphite, and cop er is deposited thereon to a thickness of a out onesixteenth of an inch to produce shells for use as parts of dies; these new shells bein identical with the shell 4, so that the rther steps in our rocess may be described with reference to s ell 4.

The die cavities in the shell are filled with lava patch, as indicated at B in Fig. 4, and the s ell is set upon a cast iron plate C, preferably about one-half inch thick and covered on the upper side b a sheet D of asbestos about one-eighth o an inch thick. A low iron frame E, open at the top and at the bottom and both longer and wi er than the shell, is placed so as to rest on the asbestos and surround the shell. The space between the sides of the pan and the frame is filled with dry molding sand F. A second iron frame G, similar to the first frame but smaller, is set in the pan so as to rest on the bottom of the latter close to the sides. The space between this second frame and the sides of the pan is 4partially filled with ground asbestos, H, and that part of the space that is above the asbestos is lled with dry molding sand I. A flux X, conveniently dehydrated borax, is poured into the pan within the space bounded by the inner frame, and the assembly is ready for the casting step.

The assembly just described, consisting of what may be termed the mold containing the copper shell partially lled with a flux, is then put into a furnace K, as Shown in Fig. 5, and is heated to a temperaturev of about 1600 degrees F. Brass, preferably almost entirely of the bata type, is melted in a separate furnace and is also brought to a temperature of about 1600 degrees E. The apparatus is so arranged that the molten brass may be poured into the mold without removing the latter from its furnace. For example, the brass may be in a pot L from which it may be poured, by tilting the pot as indicated in dotted lines in Fig. 5, into a funnel M whose spout extends into the furnace K and terminates above the mold. .The spout preferably delivers the molten brass into a distributing trough N positioned in the furnace K above the mold and having numerous erforations distributed along the bottom; t e result being that the molten metal falls upon the bottom of th'eL pan in the mold in the manner of rain. 'The molten brass unites with the copper of the pan or shell and, when it has solidified, forms vwith the latter a solid block 5 of brass (see Figs. 6 and 7) faced with a thin sheet of copper constituting a die face.

The complementary die is made by casting upon the face of the die just described, after the latter has been covered with soot, a metal suited to the purpose. For many purposes so-called Samson metal, consisting mainly of zirc, copper, and aluminum, may be em- P Oye l In Fig. 6 we have illustrated the `manner in which a white metal complementary die may be made. The copper faced brass block, after the lava patch has been removed and the sides of the an cut away, is set face up, on a cast iron p( ate O, preferably about. onehalf inch thic and around it and spaced a art therefrom is placed an iron frame P, similar to the frame E previously described. Wet molding sand Q is packed in the space between the die block and the frame. A shallow perforated steel tray 6 is inverted upon the die block. The perforations in the tray should be large, say about L.three-eighths of an inch in diameter. 1 Weights R, resting upon tall tripods S, hold v lthetray down. This assembly is heated in a furnace to about 1000 degrees F. and then, after removing it from the furnace, the moltenjSamson metal, also heated to about 1000 degrees F., is poured into the same to a depthy of three-fourths of an inch or an inch; thus producing la block 7 of Samson metal having a die face complementary to that of the other block.

After the Samson metal has cooled, the two dies are separated and then clamped together and machined. The perforated steel near the face of the white metaldie reenforces the block and keeps the adjacent metal from shrinking while cooling. The brass block needs no reenforcement, but the whlte metal block, after being machined, is preferably fitted into a cast iron tray, not shown.

Usually it is not desired that the dies fit accurately at all points because some parts of a panel should usually be compressed more than others. The dies may readily be relieved by cementing pieces of asbestos sheets to those areas on the face of the copper faced brass block where the lesser pressure is required when the dies are in use.

lWhen the metal Ais poured upon thecopper faced block it cannot occupy the space already occupied by the asbestos, and the asbestos can afterwards be removed. In Fig. 7 we have shown such a piece of asbestos T on the copper face of the brass block; the asbestos being held in place by suitable cementing means as, for example, sodium silicate.

In Figs. 8 and 9 there is illustrated a Vmodified way of producing the copper faced brass die block. Instead of using the outer frame E as a part ofthe mold, we provide a trough-shaped frame U of copper, L- shaped in cross-section, surrounding the pan and having its narrow side or flange riveted or otherwise fixed to the pan. The side walls of the pan and this frame, together with the base and the asbestos covering, produce a continuous closed chamber surrounding the pan.. The frame G which, in this instance, 1s preferably made of copper is placed as previously described, and the asbestos and molding sand are interposed between this frame and the sides of the pan or shell, as before.

In Fig. 10 the copper shall 4, instead of being pan-shaped, is simply a flat plate having the design in the center. This plate is set into a frame V, preferably of copper,

the members of which are Z-shape'd in crosssection. The copper shell rests upon the inturned flange of the frame and is riveted thereto. marginal portion of the shell. After the space within the frame G has been artially filled with a flux, as shown, the rass is poured in through the erforated tray, as heretofore described. he urpose of the perforated tray, as previous y stated, is to distribute the incoming molten metal. I the metal were all poured at one point in a single heavy steam it would melt-the co per more or less atthis point. However, y distributing the molten metal 'over substantially the entirev surface of the copper shell The frame Gl rests on the ilat.

there will be no such concentration of heat at any single point as to injure the shell.

While we have illustrated and described with particularity a preferred series of steps 5 and preferred metals, we do not wish to limit ourselves thereto; but intend to cover all p now..- and all metals or othermaterials coming within the definitions of our invention constituting the appended claims.

We claim: 1 1. The method of producing one of la pair of dies adapted to mold wood anels, which com the making of an e eetrodeposited s ell with flarin sides and having 15 the design in the under ace of the bottom wall, setting the shell 'on a su port, placing a frame, larger than the she on the support, around the shell, setting a second frame within the shell, filling the spaces between 2 the sides of the gan and the two frames with non-combustl le material, and pou molten metal into the pan in the space within the inner frame.

2. The method of producing a die mem- 25 ber which consists of setting a die, `faee up,

in a mold open at the tog, placin the assembly in an oven, and eating e same and pouring molten metal into the mold in the form of many small streams dis- 3 tributed across the length and breadth of the mold while the assembly remains in the oven.-

3. The method of producing a die member which consists in forming a co per pan- 35 like member having a bottom w adapted to constitute the die face, placing in the panlike member a continuous frame open at the top, and pourin molten brass into the s ace bounded by t e frame.

9 4. e method of producing a die member which consists in forming a co per panlike member havin a bottom w adapted to constitute the ie face, placing in the pan-like member a continuous frame open 5 uc tho top, raising tho ofthe pan-like member to about e temperature of molten brass, and uring molten into the space bounded y the frame.

5. The method of producing a die member which consists in forming a co per paulike member'havin a bottom wa adapted to constitute the 'e face, placing in the pan-like member a continuous frame open at the top, placing above the frame a trough having numerous porforuoiouo distributedover the bottom, heating the assembly to about the melting point of brass, and pourin molten brass into the trough. r

testimonylwhereof, we sign this speck` 9 cation.

FRANK M. CURRAN. CHARLES B. NORRIS. HENDRIK W. VAN STEENWYK. 

